Hi. I'm fairly new to this site but I know enough to do a search before I start asking questions. I couldn't find any real answers so here goes...

I have a 1978 Ford Bronco that had a 351m engine which blew up. I took it as an opportunity to install a 460. I have decent mechanical skills, but no space to do the extensive work needed to do an engine swap. So I found a good mechanic who is doing it for me. I found a parts truck, a 1978 Ford F250 that has a 460. Engine runs strong and is currently being installed in the Bronco. I recently asked my mechanic about the wiring harness. I asked if the existing wiring harness will hook up correctly to the 460 or if I should pull the wiring harness from the F250. He seemed unsure of the correct answer but said pull the harness because we would probably need it.

Side note: my goal with this project is to make a smog legal 460 in this Bronco. I live in California and I already spoke to a smog referee about what was necessary to make this Bronco legal with a 460 and smog compliant. The F250 parts truck had a completely original 460 with all of the necessary smog components.

So I guess my questions are:
Will I be able to use the existing wiring harness in the 78 Bronco with the 460 swapped in?
If not, will the wiring harness pulled from the 78 F250 parts truck install without any problems in the Bronco? - I don't see why it wouldn't work because the engine bay and the dash are identical. However, I have read in other posts that the rear window wiring will be in issue-
Lastly and most importantly, what should I expect to pay in order for the wiring to be done correctly on my 78 Bronco? My mechanic has a friend who owns a business wiring vehicles. This friend of my mechanic offered to wire my Bronco in trade for a car trailer I own. Labor costs only. The trailer is valued at probably around $1000 in its current condition. I do not have much knowledge about wiring vehicles, but $1000 soley in labor cost to wire a late model truck with minimal accessories seem really high to me.
Any and all comments suggestions are much appreciated. Thanks in advance.

 

I could be wrong, but you should be able to just leave the harness in place from your Bronco. The Duraspark ignition box from the 351m will be able to plug directly into the distributor from the 460 providing it is a Duraspark unit. In all reality, this is the only thing that matters. Oil and temp gauges can be made to work by swapping to the correct sending unit. The power wire on the coil will be the same. I think that covers it.

 

That is really good to know. Thanks. So I take it the existing harness in the 78 Bronco will be completely operational with the 460 installed from the 78 F250.....? This is my first time pulling a wiring harness and is seem like a lot of disconnecting and various components. It is still a pain in the a$$ to pull the harness.

Unless I am completely mistaken, the labor costs that I am paying my mechanic to install the 460 should include connecting the existing wiring harness and smog equipment correct? Not just setting the engine on the mounts and bolting it to the trans....? I know this is a conversation I should have with my mechanic and get on the same page first before there are any surprises. I just want to know what is the industry norm and what is a realistic expectation for this kind of engine swap and install. Thanks again for your help. <!-- / message -->

 

Yes and yes.

The Duraspark was used for years and as far as I know the boxes for them are all the same. You can use the same box on a SBF, BBF, FE or I6. Someone please correct me if I am wrong. If your mechanic tries to give you a line of BS, go elsewhere.

As far as the setup goes, the smog stuff should be intact from when you pulled the motor so no setup needed.

The only other hang up I could see is if the motor mounts are not the same. You may be able to use the ones from the truck in your Bronco, but I am not sure. Just have to visually compare the two. May also have some driveshaft and tranny issues if the backside of the 460 does not sit in exactly the same spot as the 351m. Only way to know is to try it.

And yes, talk with your mechanic and get things straightened out. You need to know UP FRONT what he plans on doing and what he will charge you.

Honestly, $1000 sounds a bit high for what is probably a bolt in change. Even if the mounts need to be swapped and the driveshafts are not right, thats still ridiculous.

This swap is not that hard, and honestly you could do this at home in your garage with nothing but a cherry picker.

 

From what I have read when researching a 460 swap, you need to use the motor mount towers that are attached to the frame of the donor truck. They should bolt into your Bronco, but there may be some rivets and bolts mixed that have to be removed to get the towers out of each vehicle. The towers are supposedly stamped on the back side with the engine size i.e. 460, 351 etc. If you use the 460 towers you can use stock motor mounts instead of ordering the high $$ swap mounts. Unfortunately I didn't find this out until I already had the ~$150 mounts. Good luck with your swap.

 

Thanks for the reply. I have already order the shackle mounts so I might try to return them. I have read a bunch of swap articles and never came across that info. But thanks for the heads up. Ill take it from a guy who did the swap already.

 

All the aftermarket motor mounts are made to use the 351m-400 towers. There are no id marks that say what motor they fit stamped on them. There is no such thing as a "460tower" Ford never put a 460 in a Dent Side 4x4. They are both bolted on, 4 through bolts and 2 bolts on the top. If you don't have motor mounts yet get the West Coast Bronco mounts. They are the best ones out there as they are not vulcanized junk like L&L & Transdapt sells The wiring will all work, plug in and go.

 

Thanks Mark.
The mounts i bought were from Bronco Graveyard. They are shackle mounts that seem to have more attributes for offroad over the ones with the vucalnized rubber and steel plate like u were talking about. Let me know what you think as they are not on the Bronco yet. Appreciate your input. Thanks

 

The mounts from bronco graveyard with poly bushings are made by westcoast broncos. They are excellent. I used them in a recent swap myself and everything lines up perfectly.

Your 351m distributor and ignition system and wiring harness will work with the 460.